A young woman is stabbed to death on the floor of her apartment on Sydney's northern beaches. By the time police find the body of Rachelle Yeo inside her Curl Curl home, her alleged killer has fled, driving north to Newcastle airport.

But police then get a major breakthrough - a single fingerprint on a railing outside her property. Forensic officers dust it, digitally photograph it and transmit the image back to analysts waiting in an office at Parramatta. Within minutes they run it through a national database of the 3 million prints on record in Australia. They get a match - a former partner of the 31-year-old who has recently boarded a flight from Newcastle to Brisbane.

Within 120 minutes of finding the dead body, police now have a person of interest. Their counterparts in Queensland wait for him as he steps off the plane and he is arrested just hours after the crime is committed.

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The whole investigation unfolds like the plot of an American crime show. And while Hollywood might have viewers believing such an outcome has been easily achievable for police for some time, in reality results like this are being heralded as a breakthrough in forensic investigations, not just in NSW but around the world.

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''There's a lot of myths that are generated by the likes of CSI and NCIS,'' said Inspector David Forbes from the NSW Police crime scene services branch. ''It's annoying on TV where they will automatically get a DNA result. There's a lot more work than that. But it is getting quicker - not quite like on the TV [where you] have it solved in 45 minutes - but the technology is going ahead in leaps and bounds.''

The forensic services branch of the NSW Police Force was established in 1995 and now consists of close to 1000 employees including fingerprint and ballistics analysts.

The majority, however, belong to the crime scene branch - officers rostered at all times of the day and sent all over the state to major crimes to collect and record physical evidence. The bigger and more complex the crime, the longer this whole process can take.

The crime scene investigators who attended the murder of five members of the Lin family in their North Epping home in July 2009 spent close to a full week at the house.

Unlike on TV, it is not the same officers who go back to the lab and analyse the samples and interview suspects and chase down an offender. These are experienced officers who only attend crime scenes and have spent up to five years learning their craft.

If it is not done properly there is a risk of contamination, misinterpretation and evidence being lost. Serious investigations can be jeopardised from the outset and that is why, the police stress, it is ''vitally important to get the science right from the beginning''.

That process is now being assisted by recent changes in technology which include devices that allow real-time identification of fingerprints and faster ways to analyse bullets and casings found at scenes and test if they have been used in other crimes.

The investigation into the death of Yeo is not the only example of how the next generation of forensic work is bringing about quicker arrests for serious crimes.

Officers in the Sydney region this year arrested a man with a gun. As they took him in for questioning, detectives took the firearm to the ballistics experts at the Sydney Police Centre in Surry Hills. They test-fired the weapon and ran the bullets and casings through their latest million-dollar machine known as Integrated Ballistics Identification System.

The system allowed police to do a 3D examination of the bullets and casings in minutes, then check them against 40,000 images of bullets and casings found at other crime scenes. Within 60 minutes of receiving the gun, ballistic experts discovered the firearm had been used in a recent attempted murder.